Task 2 for Statistic 2008-2009

October 21, 2008 — parvian

2.58

An automobile manufacturer is concerned about a possible recall of its best – selling four door sedan. If there were a call, there is 0,25 probability that a defect is in the brake system. 0,18 in the transmission, o,17 in the fuel system, and 0,40 in some other area.

What is the probability that the defect the breaks or the fueling system if the probability of defects in both system simultaneously is 0,15?

2.70

Factory workers are constantly encouraged to practice zero tolerance when it comes to accidents in factories. Accidents can occur because the working environment or conditions themselves are unsafe. On the otherhand, accident can occur due to carelessness or so called, human error. In addition, the workers shift 07.00 AM – 03.00 PM ( day shift ), 03.00 PM – 11.00 PM ( evening shift ) and 11.00 PM – 07.00 AM ( graveyard time ) may be a factor. During the last year, 300 accidents have occured. The percentages of the accidents for the condition combinations are follows :

Shift
Unsafe Conditions
Human Error
Day
5%
52%
Evening
6%
25%
Graveyard
2%
30%

If an accident report is select randomly from the 300 report

  • what is the probability that the accident occured due to human error?
  • what is the probability that the accident occured due to unsafe condition?

2.88

The probability that the head of a household is home when a telemarketing representative calls is 0,4. Given that the head of the house is home, the probability that the head of the house is home and goods being bought from the company

2.106

A regional telephone company operates three identical relay stations at different locations. During one year period, the number of malfunctions reported by each station and the causes are shown below

Station A B C
Problem with electricity supplied
2
1
1
Computer malfunction
4
3
2
Malfunctioning electrical equipment
5
4
2
Caused by other human errors
7
7
5

Suppose that a malfunction was reported and it was found to be caused by other human errors. What is the probability that it came from station C ?

The answers of this tasks will be upload on Thursday 23 Oct 2008

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